Assembly of complex mechanical seal for vertical multiple stage pump

ABSTRACT

Complex mechanical seal for vertical multiple stage pump comprises: a hollow cylinder fixed plate positioned in the final stage of outlet gate in the vertical multiple stage pump, it is coupled with an inner wall surface of fixed barrel to form a sealed face, the bottom hole of fixed barrel is used the passage of pump axle; a long axle bushing in the inner part of the fixed plate is fixed on the pump axle; a balance plate is positioned below long axle bushing and combined with said long axle bushing becoming one part of it, the circumference of balance plate has a promotion flange to divide with the inner wall surface to form a gap; the mechanical seal is fixed on the upper place of the balance plate and fixed on long axle bushing; and a return water passage which communicated with the upper part of balance plate and connected to inlet of pump, thus within the fixed plate, the high pressure region A and low pressure region B formed at the lower part and upper part respectively are need as the pushing force of the balance axle. Simultaneously, the complex structure of balance plate and mechanical seal is more easily and quickly in assembly and disassembly.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an assembly of complex mechanical seal for vertical multiple stage pump. More particularly, the invention relates to a cassette type assembly of complex mechanical seal comprised of balance plate and mechanical seal, whereby to make the balance plate and mechanical seal to be easily and quickly changed so as to guarantee the efficacy of pump.

[0002] A balance of horizontally pushing forces for a vertical multiple stage pump has various methods to resolve it effectively, such as to use bearing directly against the horizontally pushing force, or to use the balance holes, or to use balance dice. However, it is generally to adapt the balance plate in this field. When the balance plate in used as a balance apparatus for a vertical multiple stage pump the structure of mechanical seal in arranged equipped on the upper part of the pump. Thus the position of the structure of the mechanical seal provides a leaking out gate in orders to prevent the gas stayed on the upper part of pump, whereby to guarantee the mechanical seal able to be cool and lubricant by the transportation liquid, so as to keep the sealing of the pump and the stabilizing work.

[0003] In addition, in the conventional balance apparatus, the gas between the balance plate and fixed elements will increase the amount of leaking out due to the increasing of leaking out the pressure to lead the descending of the efficacy of pump. Further, the size of balance palate is to close the inlet size of blade wheel and it is an independent apparatus. Thus, the vertical and the horizontal size need a certain space to satisfy the requirement of operation. Therefore, the maintenance work of assembling and disassembling is much difficult so as to waste a long time to disassemble and assemble mechanical seal and balance plate.

[0004] The inventor finds the balance apparatus of the conventional pump accompanying with the above mentioned defects. A cassette complex structure for a novel mechanical seal and balance plate is provided. In addition to quickly execute the works of assembling and disassembling, it is to maintain the efficacy of pump not to be influenced due to the changing of pressure, which is the main object of the present invention.

[0005] According to the present invention, the mechanical seal and balance plate are combined together. Thus the whole structure is more closely and firmly packed and save the space, which is the further object of the present invention.

[0006] The present invention provides a complex mechanical seal for vertical multiple stage pump, which comprises: a hollow cylinder fixed plate positioned in the final stage of outlet gate in the vertical multiple stage pump, it is coupled with an inner wall surface of fixed barrel to form a sealed face, the bottom hole of fixed barrel is used the passage of pump axle; a long axle bushing in the inner part of the fixed plate is fixed on the pump axle; a balance plate is positioned below long axle bushing and combined with said long axle bushing becoming one part of it, the circumference of balance plate has a promotion flange to divide with the inner wall surface to form a gap; the mechanical seal is fixed on the upper place of the balance plate and fixed on long axle bushing; and a return water passage which communicated to the upper part of balance plate and connected to inlet of pump, thus within the fixed plate, the high pressure region A and low pressure region B formed at the lower part and the upper part respectively are need as the pushing force of the balance axle. Simultaneously, the complex structure of balance plate and mechanical seal is more easily and quickly in assembly and disassembly.

[0007] According to the present invention, the mechanical seal and balance plate are combined together, and the circumference of balance plate is to form various annually grooves. Said combined structure is able to keep a small distance with the inner face of circumference of fixed barrel. Thus the combination of balance plate and axle is to keep a same gap with the inner face during rotating and pressure changing. The amount of leaking out is not influenced to keep unchanged so as to maintain the efficacy of the pump. Besides, according to the present invention, the combined mechanical seal and balance plate are disassembling and assembling together from a pump axle. Therefore, the works of disassembling and assembling are easy and the maintenance is easily.

[0008] According to the present invention, the complex structure of mechanical seal and balance plate is to form an outlet pipe line connected to inlet. Thus when the pump starts to operate, it is able to outlet the air automatically. This is another object of the present invention.

[0009] The present invention will be apparent in its novelty and features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a schematic view showing the complex structure of mechanical seal and balance plate of the present invention to be arranged on the upper part of the last blade wheel within the vertical multiple stage pump, in which the conventional elements are omitted.

[0011]FIG. 2 is an enlarged view showing the complex structure of mechanical seal and balance plate in the FIG. 1 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012] Firstly, referring to FIG. 1, a housing 1 within a vertical multiple stage pump is located a space of the outlet position of the upper part of last blade wheel 2. The assembly of complex mechanical seal 4 of the present invention is arranged on pump axle 3. As used in the conventional method, the pump axle 3 via coupling 5 is rotated by motor (not shown).

[0013] Referring to FIGS. 1 and 2, the assembly of complex mechanical seal 4 is including a hollow cylinder fixed barrel 6 arranged on the tope of housing 1. It is used to form a balance house and the pump axle 3 passed through the bottom hole 601 of fixed barrel 6. In the inner the fixed barrel 6, a set of long axle bushing 7 on the pump axle 3 is screwed with a bolt 8 to fix on the said pump axle 3 and is able to rotate with said pump axle 3. A plate of balance plate 9 is formed under the long axle bushing 7, which is formed a predetermined gap around the arising flange 901 of the circumference of the balance plate 9 and the inner wall surface 602 of the fixed barrel 6. Further, the circumference of the flange 901 is to form plural annual groove 902. Thus the balance plate 9 in the inner space of the fixed barrel 6 forms a high pressure region A under the lower part of the balance 9 and forms a low pressure region B on the upper part of the balance plate 9. On the top part of the balance plate 9, the long axle bushing 7 fixes a conventional mechanical seal 10 to combine with the balance plate 9 together. Via a axle sealed gland 11, the low pressure region B is covered, and said low pressure region B is communicated with the inlet gate via return water passages 603,604.

[0014] According to the present invention, when the multiple stage pump starts to rotate, the air in the low pressure region B is able to be outflow automatically via the return passages 603,604 due to the rotation of balance barrel 9 and mechanical seal 10. Thus it is not needed to do the manual operation as done in the conventional ones. Simultaneously, as the low pressure region B is connected to the inlet gate of the pump, it is able to keep the low pressure state. Therefore, the outflow of most high pressure water via the last stage of the pump is at outlet gate (drain port) 101 and to be outlet from the housing 1 and part of high pressure water is able to act on the balance plate 9 via the bottom hole 601, to taking advantage of the differential pressure forms an arising pushing force to act on the balance plate 9 whereby to balance the resultant force formed by down forward vertical pushing force of the blade wheel and the gravity of blade wheel of the pump and so on.

[0015] Taking advantage of the present invention, in case the pressure of the high pressure water to be outlet is arisen, and due to the gap of the flange 901 in the balance plate 9 and the inner wall surface 602 of the fixed barrel 6 kept unchanged, the design of the multiple annual groove is able to buffer the flowing of water stream. Therefore, the amount of leaking out of the high pressure of pump enters into the balance room can be kept at certain rate and is used to cool and lubricant the mechanical seal 10, so as to keep the efficacy of pump.

[0016] Further, taking advantage of the present invention, the balance plate 9 and mechanical seal 10 are combined together to form a complex structure. Thus, as shown in FIGS. 1 and 2, the maintenance and repaired operation are only to dissemble the mechanical seal gland 11, i.e. to take down the complex structure from the pump axle 3, so that the maintenance and repaired operation become more easily and quickly.

[0017] The feature and preferred embodiments of the prevent invention have been described in foregoing specification and the explanation of vertical multiple stage pump is done. The invention is also suitable for the pushing force of other kinds of pump. Variations and changes which may be made by those skilled in the art are without departing from the scope of the present invention.

LISTS OF SYMBOL

[0018]1 housing

[0019]2 blade wheel

[0020]3 pump axle

[0021]4 assembly of complex mechanical seal

[0022]5 coupling

[0023]6 fixed barrel

[0024]7 long axle bushing

[0025]8 bolt

[0026]9 balance plate

[0027]10 mechanical seal

[0028]11 gland

[0029]101 outlet gate (drain port)

[0030]601 bottom hole

[0031]602 inner wall surface

[0032]603,604 return water passage

[0033]901 flange

[0034]902 annual groove

[0035] A high pressure region

[0036] B low pressure region 

What is claimed is:
 1. A complex mechanical seal for vertical multiple stage pump, comprising: a hollow cylinder fixed plate positioned in the final stage of outlet gate in the vertical multiple stage pump, it is coupled with an inner wall surface of fixed barrel to form a sealed face, the bottom hole of fixed barrel is used the passage of pump axle; a long axle bushing in the inner part of the fixed plate is fixed on the pump axle; a balance plate is positioned below long axle bushing and combined with said long axle bushing becoming one part of it, the circumference of balance plate has a promotion flange to divide with the inner wall surface to form a gap; the mechanical seal is fixed on the upper place of the balance plate and fixed on long axle bushing; and a return water passage which communicated with the upper part of balance plate and connected to inlet of pump, thus within the fixed plate, the high pressure region A and low pressure region B formed at the lower part and upper part respectively are need as the pushing force of the balance axle whereby to balance the resultant force formed by down forward vertical pushing force of the blade wheel.
 2. A complex mechanical seal for vertical multiple stage pump according to claim 1, wherein the circumference of the flange of balance plate being formed plural annual grooves.
 3. A complex mechanical seal for vertical multiple stage pump according to claim 1, wherein a return water passage which communicated with the upper part of balance plate and connected to inlet of pump.
 4. A complex mechanical seal for vertical multiple stage pump according to claim 1, wherein the return water passage arranged on the inner part of pump housing to be returned to the inlet gate of pump. 